Carbonadium was created when the Russians synthesized it in an attempt to recreate their own Adamantium. While not as durable as adamantium, it is still next ot unbreakable yet much more flexible. Carbonadium is poisonous to organics like most heavy metals, and slowly poisons those who use it.
Because of its toxicity the metal has the ability to disrupt mutant healing factors. The Russians used the metal to create deadly coils for their super soldier project candidate Omega Red. In order to survive the metals slow poison, Omega Red is forced to drain the life energies of others to survive.
The only known way to stabilize this condition is with the Carbonadium Synthesizer.